Coxa vara with proximal femoral growth arrest as a possible consequence of extracorporeal membrane oxygenation: a case report

Coxa vara is an abnormality of the proximal femur with a decreased neck-shaft angle and resulting leg-length discrepancy, has been associated with conditions such as congenital coxa vara, traumatic injury, sepsis, rickets, vascular damage, or metabolic disorders; however its possible relationship with extracorporeal membrane oxygenation has been recently reported. A full term girl was born with a total infradiaphragmatic anomalous pulmonary venous drainage, at the age of 12 days, an anastomosis of the pulmonary venous trunk with the left auricle and closure of the auricular septal defect was performed; during this procedure extracorporeal membrane oxygenation was used during 104 minutes, no neonatal sepsis was developed. She had no orthopedic issues until she was 3 years and 10 months old, when she presented with limp related to the right lower limb, with no pain. She had a leg-length discrepancy of 2 cm (right - left), limited right hip abduction to 25°, and internal rotation to 5°, also had a positive Trendelenburg test. No flexion/extension abnormalities. Anteroposterior radiographs and magnetic resonance revealed coxa vara with proximal femoral growth arrest. A valgus osteotomy with greater trochanteric epiphysiodesis was performed. At the eight month follow-up, she had no hip pain, better hip range of motion, no difficulties with recreational activities and the osteotomy healed. Another four similar cases had been reported with similar outcome, we think that it will be recommendable to take images in patients with this background and limb leg-length discrepancy or abnormal range of motion.